Insights from the world’s leading scientists on evolution, climate change, technology and extraterrestrial life. We are the only species of the billions of species that have existed on Earth that has shown an aptitude for radios and even we failed to build one during the first 99% of our 7 million year history, says Australia National University’s Charley Lineweaver.
Are Homo sapiens a one-off, genetic accident?
Scientists have identified a group of planets outside our solar system where the same chemical conditions that may have led to life on Earth exist in what they call the Abiogenesis Zone. It’s also possible that if there is extraterrestrial life, that it has, or will, develop in a totally different way than it did on Earth.
“I’m not sure how contingent life is, but given that we only have one example so far, it makes sense to look for places that are most like us,” said Cambridge University astrochemist, Paul Rimmer. “There’s an important distinction between what is necessary and what is sufficient. The building blocks are necessary, but they may not be sufficient, it’s possible you could mix them for billions of years and nothing happens. But you want to at least look at the places where the necessary things exist.
Rimmer speculates that life may have come from non-life as one big accident. This seems highly unlikely, at least given the way our universe is set up, so if it’s that way, then we are probably the only intelligent life in the universe, maybe the only life at all.
For what purpose did the human brain evolve?
“For what purpose did the human brain evolve?” It is a question that has puzzled scientists for decades, and was answered in 2010 by Colin Blakemore, an Oxford University neurobiologist who argued that a mutation in the brain of a single human being 200,000 years ago turned intellectually able primates into a super-intelligent species that would conquer the world. Homo sapiens appears to be genetic accident. Or are we?
Lifespan of Technological Civilizations
The rate of growth of new technologies is often proportional to past knowledge, writes Harvard’s Avi Loeb in How to Search for Dead Cosmic Civilizations, leading to an exponential advance over time. This explosive process implies that very quickly after a civilization reaches technological maturity, it will develop the means for its own destruction through climate change, for example, or nuclear, biological or chemical weapons. Developments of this type, over mere hundreds of years, would appear abrupt in the cosmic perspective of billions of years. If such self-destruction is common, this could explain Fermi’s paradox, which asks “where is everybody?”—and could imply that relics of dead civilizations should be abundant in space.
Alien Worlds & the Fate of the Earth
In a brilliant display of intuition vs evidence, astrophysicist Adam Frank at the University of Rochester and author of “Light of the Stars: Alien Worlds and the Fate of the Earth”, proposed in his New York Times article “Yes, There Have Been Aliens”, that “while we do not know if any advanced extraterrestrial civilizations currently exist in our galaxy, extraterrestrial civilizations almost certainly existed at one time or another in the evolution of the cosmos. the degree of pessimism required to doubt the existence, at some point in time, of an advanced extraterrestrial civilization borders on the irrational. We now have enough information to conclude that they almost certainly existed at some point in cosmic history.”
Frank writes that this probability is not an abstraction, not just a pure number. Instead, he says, it represents something very real: “10 billion trillion planets existing in the right place for nature to have at it. Each world is place where winds may blow over mountains, where mists may rise in valleys, where seas may churn and rivers may flow. (Note our solar system has two worlds in the Goldilocks zone — Earth and Mars — and both have had winds, seas and rivers). When you hold that image in your mind, you see something remarkable: The pessimism line actually represents the 10 billion trillion times the universe has run its experiment with planets and life.”
Frank’s argument have their appeal, countered Ross Andersen in The Atlantic, but it is an appeal to intuition: “The simple fact is that no matter how much we wish to live in a universe that teems with life—and many of us wish quite fervently—we haven’t the slightest clue how often it evolves. Indeed, we aren’t even sure how life arose on this planet. We have our just-so stories about lightning strikes and volcanic vents, but no one has come close to duplicating abiogenesis in a lab. Nor do we know whether basic organisms reliably evolve into beings like us.”
The Daily Galaxy